Tooth construction



U. M. RICHARDSON TOOTH CONSTRUCTION Filed April 17. 1922 Patented Oct. 30, 1923.

UNITED STATES 1,472,678 PATENT OFFICE.

ULYSSES H- BICHARDSON, OF CHICAGO, ILLINOIS, ASSIGNOR OF ONE-HALF TO JLMES B. CROWLEY, OF CHICAGO, ILLINOI S.

TOOTH CONSTRUCTION.

Application filed April 17, 1 922. Serial No. 554,257.

To all whom it may concern:

Be it known that I ULYSSHS M. RICHARD- soN, a citizen of the Ilnited States, and resident of Chicago, in the county of Cook and 6 State of Illinois, have invented certain new and useful Improvements in Tooth Construction, of which the following is a specification.

My invention relates to dental practice 10 and particularly to artificial tooth construction and arrangement relative to plate work.

In the construction of full or partial plates, it is customary to rovide, whenever possible, an attaching device, usually in the 5 form of a lateral projection from a stump, and a cooperating clasp carried by the plate.

This attaching device necessarily lies above the gums and in the space separating the tooth therefrom and the strength of-the plate is dependent upon the body of rubber which may be accommodated in that space.

It is essential that the tooth be provided with an anchoring device which in common usage consists of a pin projecting from the 2 under surface of t e tooth and provided .with a head adapted to be embedded in the vulcanized rubber com rising the "plate.

The head of the pin wi I, therefore, reach 'a oint adjacent to the attachment device 8 and as heretofore used, restrict the crosssection of rubber at that point.

\ In my im roved construction I utilize a similar attac ing device and employ a tooth having an anchoring pin, but I hollow out the tooth adjacent to the pin and provide a cavit of ample size within which a substantia body of rubber may be received. The head of the pin is thereby anchored in a body of rubber and a full cross section of 40 heretofore weak. The result is secured without weakenin 'cost of menu acture thereof.

The shape and,- more particularly, the thickness of the different teeth, together with their roper location with respect to the plate-ri ge, determines to a considerable extent the shape and disposition of the rid Jap or mounting surfaces of the severa teeth. For exam la, the incisors are comparative] thin in dy and their axes properl lie orward of the plate-ridge; consequent y, the ridge-lap or mounting surface of each incisor must be one which extends at an'oblique angle to the axis of the material is provided at the point which wasthe tooth or increasing the.

tooth, while the molars, being thicker in body, are properly positioned with their axes more directl over or atop the plateridge, and their ridge-lap or mounting surfaces usually comprise a channel or groove which provides a shoulder for extension partly over or across the plate-ridge. I am aware that artificial teeth have heretofore been )rovided with headed pins which project rom their ridge-lap or mounting surfaces, and that countersunk headed pins have been used; My invention is believed to constitute an easil recognizable improvement upon each 0 these former methods. By my arrangement of the headed pin in a cavity or recess in the tooth body, I provide for a sufliciently deep investment of the pin-head in the vulcanized rubber to obtain a firm and structurally strong attachment of the tooth to the plate and at the same time obtain a thicker rubber plate structure at this im ortant point.

The invention wil be more readily understood by reference to the accompanying drawing, in which,

Fi 1 is an elevation of a partial denture tti va ich my improved tooth has been app Fig. 2 is a lon itudinal vertical sectional view therethroug Fig. 3 is a transverse vertical sectional view on the line 8 -3 of Fig. 2'

Fig. 4 is aside elevation of t e construction shown in Fig. 3, and,

Fig. 5 is a side view of an individual tooth.

While the improved tooth is adapted for general application to all forms of plate work, isv is shown in connection with a partial late consistin of a vu'lcanite saddle 10, tiie teeth of'di erent forms being indicated at 11. From' the cross section shown inFigs. 3 and 5 it will be observed that my arrangement of the cavit or recess in the tooth body affords a su stantially toothsup orting shoulder without weakening the toot structure. The tooth is particularly useful in cases where an attac ing device is employed. Such a device may consist of an arm 12, anchored to a stum 13, and projecting horizontally in line with the top of the um indicated at 14. A clasp 15 is provide with projections 16, which serve as a means for anchoring the clasp in the plate. As shown in Figs. 2 and 3, the U-shaped clasp is adapted to cooperate with the arm 12, to hold the plate in position. When a tooth having the usual anchoring pin is applied adjacent to a fastening device, it results in weakening the structure due to the fact that there is an insuflicient cross section of material at the point of engagement. In order to overcome this deficiency I provide the tooth 11 with a headed pin 17, the pin being substantially centrally located within a cavity 18 formed in the lower face of the tooth. Ihe pin head need not project outside of the plane of the lower surface but is nevertheless securely held Within a suitable body of vulcanite such asis indicated at 19. There is therefore no weakening of the plate due to the employment of any of the well known forms of attaching devices.

20 Furthermore by my arrangement of the pin at a pronounced oblique angle to the axis of the tooth, .twistin of the tooth by this action is prevented and consequently the liability of loosening of the tooth in this manner is obviated. a

The application of the improvement is adapted to be made to many diiferent forms of artificial dentures, only one illustration of such forms being provided.

I claim:

An artificial tooth havin a ridge-lap or mounting surface providef with a cavity extending from said surface into the body of the tooth, and a headed pin secured in said'body toproject from the wall of said cavity at a pronounced angle to the vertical axis of the tooth the headed end of said pin being substantially flush with said mountin surface.

igned at Chicago, 11]., this 14th day of April, 1922.

. ULYSSES M. RICHARDSON.

DISCLAIMER 1,472 678.-Ulysses M. Richardson, Ohicgo, Ill. Too-rs Cohefiaficnon. Patent d ed-0mm 30, 1923. Disclaimer ed May 6, 1932, by the Pam, and the ee of one-half interest, James B. Crowley.

-Hereby disclaim from the scope of the claim of said patent all single pin artificial teeth which are not designed fqzfireeeing into a rubber plate to be vulcanized therein to form a. permanent union; such teeth which have a part of the well'of the cavity substantially pndercut to form an overhen portion, which have wells on less than tzro gidee of the pin, and which do not ave the pin eecured to the lingual mde 1W Gazette May 24, 19.93. 

